초록 ▼

A supercharged engine has a geometric compression ratio of more than 8.5, and engine specifications are set to establish a relation, Y≥-1.75X+10, in which an intake port closing timing Y is expressed by a crank angle after the piston reaches BDC and an overlapping angle X is expressed by a crank ang

A supercharged engine has a geometric compression ratio of more than 8.5, and engine specifications are set to establish a relation, Y≥-1.75X+10, in which an intake port closing timing Y is expressed by a crank angle after the piston reaches BDC and an overlapping angle X is expressed by a crank angle for an overlapping time period during which the intake valve and exhaust valve are both open.

대표청구항 ▼

A supercharged engine comprising: a cylinder; a piston slidably received in said cylinder and reciprocatingly movable therein, said piston and said cylinder defining a combustion chamber therebetween, the engine having a geometric compression ratio of at least 8.5; a crank rotatably mounted in the

A supercharged engine comprising: a cylinder; a piston slidably received in said cylinder and reciprocatingly movable therein, said piston and said cylinder defining a combustion chamber therebetween, the engine having a geometric compression ratio of at least 8.5; a crank rotatably mounted in the engine and operatively connected to said piston, said crank limiting reciprocal movement of said piston within said cylinder between a top dead center position and a bottom dead center position, and said crank rotating as said piston reciprocates in said cylinder; an engine output means operatively connected to said crank for generating an engine output from the rotation of said crank; an intake port means open to said combustion chamber, and through which charges of intake air pass to said combustion chamber; an intake passage open to said intake port means; a mechanical supercharger operatively disposed in said intake passage and connected to said engine output means so as to be driven by the engine output for pressurizing the charges of intake air supplied to said combustion chamber through said intake port means; an intake valve operatively disposed in said intake port means for opening and closing to open and close said intake port means; an exhaust port means open to said combustion chamber and through which exhaust gases generated in said chamber are discharged therefrom; an exhaust valve operatively disposed in said exhaust port means for opening and closing to open and close said exhaust port means; the opening and closing of said valves being based on a valve lift of 1 mm, and the engine having a valve timing which can be operatively established to satisfy the equation Y≥-1.75X+10 wherein Y is the timing of the closing of said intake port means as represented by the crank angle taken between when the piston is at the bottom dead center position and when the intake valve is closed, and X is an overlap angle representing a time period during which both said intake valve and said exhaust valve are open and equal to the crank angle take between when the intake valve is open and when the exhaust valve is closed.